Generally, a dictionary including a number of bound inner pages each recorded with many words is provided with first letter indexes meeting its intrinsic use purpose. For example, index blocks indicative of the same first letter of words recorded on each inner page are provided at front and back sides of the inner page, respectively. The index blocks on the sides of inner pages are arranged such that the same ones indicative of the same letter are positioned at the same level of the inner pages, while different ones indicative of different letters from one another are stepwise positioned in alphabetical order when viewed at one side of the dictionary. Using the first letter indexes, a user can look up a desired word in the dictionary.
Although such a dictionary includes indexes, it encounters problems of a lot of time taken to search the dictionary for desired words and a difficulty in the search because the indexes are only indicative of the first letters of words and numerous words recorded on inner pages include the same first letter.
For example, where a word "STAR" is to be searched for, the index block indicative of the first letter of "STAR", namely, "S" is first looked up from index blocks formed on inner pages in the dictionary. Thereafter, inner pages recorded with words whose second letters are "T" are looked up while turning over left and right the inner pages recorded with words whose first letters are "S". Subsequently, an inner page or inner pages recorded with words whose third words are "A" are looked up. Finally, the inner page recorded with the word "STAR" whose fourth word is "R" is looked up. Accordingly, there are problems of a lot of time and effort to search for words.
Meanwhile, the applicant has proposed an atlas provided with colored indexes capable of rapidly looking up a map of a desired place. This atlas is disclosed in U.S. Pat. No. 5,306,048 issued on Apr. 26, 1994.
The atlas is provided with index blocks recorded with place names of maps on front and back sides of its inner pages. Index blocks indicative of the same place name are printed with the same color, while adjacent index blocks on each inner page are printed with different colors from each other. Index block indicative of the map name of each inner page is printed with a color darker than those of other index blocks on the inner page. With such index blocks, it is possible to search for a map of a desired place conveniently and rapidly.
However, since the patent relates to an atlas provided with index blocks indicative of specified place name, it can not be applied to a dictionary recorded with words which are numerous combinations of same and different alphabet letters. Where index blocks of the dictionary including a number of bound inner pages are printed with different colors, as in the above-mentioned patent, there are problems of a greatly increased print cost and a complex printing process.